I have a 05 sedan i just bought a month ago. it say i should get 25 hwy 18 city average. I'm using 87 octance at 2.25a gal. fill the tank too the top and reset my trip meter. At 83 miles i'm already at 3/4 of a tank. I get average 305-315 miles off a full tank.

Am i burning too much Fuel, I think so
PLEASE HELPPPPPPPPPPPPPPPPPPPPP :-(

 

Your gas gauge is not exactly representative of how much fuel is in your tank, it's just an estimate. Also, the EPA estimates are worthless. Your driving style and terrain (change in elevation) will be the largest factors in determining your mileage. This isn't just for G's, it's every car. Your car is fine.

 

Thanks twin,
i just hate when i just fill up at night then wake up in the morning driving and gauage already start too move. I'm thinking am i dumping fuel while driving.

 

I always use premium, if you do the math it's only a few bucks more and it will give you a bit better mileage plus burns cleaner. Premium in OR is 92 octane not sure bout you state. There are many factor for mileage, your driving style may be one or all city driving ect. I put a K&N drop in when I installed my Z-tube and notice a pretty huge gain in mileage. So I would suggest get premium and change filter, if you still don't notice a change then take it easy on the petal!(hard to do after z-tube install!)

 

Iight i will stop using 87 and change to 93 and hopefully i can get my power back

 

these cars are designed for premium fuel. while you can get away with using lower grade gasoline, it is not recommended as power and fuel mileage will suffer.

 

305-315 is a hair more then what i average.

I only pull 290miles before i'm near E. i average 16mpg in the winter and 18mpg now in spring/summer weather.

87 can hurt your MPG SLIGHTLY but its more about the car knocking and pinging from the wrong fuel rating.

 

I just did 350 miles on Premium fuel, and had 4.5 gallons left. When I filled up.

 

2005 G35 owner's manual (page 9-3) recommends to "Use unleaded regular gasoline with an octane rating of at least 87 AKI (Anti-Knock Index) number" for automatic transmission model and "Use unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number" for manual transmission models. However it recommends premium fuel for "improved vehicle performance".

So it is not true that these cars are designed for premium fuel only. I use 87 grade gasoline and usually get around 18 mpg in Chicago city driving.

 

if you are getting 300 to the tank (assuming you only fill 17-18 gallons), you're getting 17-18 mpg so what's the problem? If your auto or drive mostly in the city these are good numbers. i typically barely crack 16 mpg, but I have a heavy foot.

 

^ +100...... and G35 was never supposed to be a fuel efficient economy car.

 

10.3:1 CR and you want to run 87?

unless you are positive you can keep it under 4 grand, sounds like a gamble to me.

 

All city: 280ish to 300ish.. $45 bucks for a full tank of premium (93). I believe I average fine enough, but I fill the G up every 2 weeks.. I drive everyday but try not to stomp on the pedal. As long as Im pushing for 1 1/2 - 2 weeks every fill up, Im good.